The William C. Gast Business Library is located in Room 50 of the Law College Building across from the Eppley Center. It is the largest of the branches at MSU Libraries and has three business librarians, two support staff and approximately twenty student employees.

The library provides seating for 499 and has wireless access to the internet throughout the facility. There are 7 group study rooms available to students, faculty and staff. Laser printing, including color, is available from the computers or laptops through MSU Print accounts. Room 22 serves as an instruction and computer lab with 24 seats. The branch is open 99 hours each week during the fall and spring semesters. The Library serves the Broad College of Business and the School of Human Resources and Labor Relations.

Unique among the Business Library's holdings is the Michigan Public Sector Agreement Collection. The library is also the designated repository for MERC public sector fact-finding reports and the police and fire compulsory interest arbitration awards provided for by Public Act 312 (1969).